Device for production of sheet metal objects of truncated cone shape



Nov. 7, 1967 B. OHLSSON 3,350,914

DEVICE FOR PRODUCTION OF SHEET METAL OBJECTS OF TRUNCATED GONE SHAPE Filed Aug. 10, 1964 4 Sheets-Sheet 1 lNYENTO R OLOF BERTIL OHLS SUN ATTORN EYS Nov. 7, 1967 o. B. OHLSSON 3,350,914

DEVICE FOR PRODUCTION OF SHEET METAL OBJECTS OF TRUNCATED CONE SHAPE Filed Aug. 10, 19 64 4 Sheets-Sheet 2 Fig. 2

INVENTOR OLOF BERTM. OHLSSON 5 ATTORNEYS Nov. 7', 1967 o. s. OHLSSON 3,350,914

DEVICE FOR PRODUCTION OF SHEET METAL OBJECTS Filed Aug. 10, 1964 OF TRUNCATED CONE SHAPE 4 Sheets-Sheet 5 INVENTOQ o25 sso-w 1| s I [Hill] I l K [Ill OLOF BERTIL B k4 ATTORNEYJ O. B. OHLSSON 3,350,914 DEVICE FOR PRODUCTION OF SHEET METAL OBJECTS Ndv. '7, 1967 OF TRUNCATED CONE SHAPE 4 Sheets-Sheet ,4

Filed Aug. 10, 1964 N VENTOR OLOF BERTIL'OHLSS'ON 1B]- W431? ATTORNEYS United States Patent 3,350,914 DEVICE FOR PRODUCTION OF SHEET METAL OBJECTS OF TRUNCATED CONE SHAPE Olof Bertil Ohlsson, 2 Sommarvadersgatan, Goteborg, Sweden Filed Aug. 10, 1964, Ser. No. 388,398 3 Claims. (Cl. 72-393) The present invention relates to a device for production of objects in the shape of a truncated cone, by reshaping cylindrical sheet metal blanks.

The device according to the invent-ion is substantially characterised by the end of a number of jaws in the shape of segments of a cylinder being pivotally journalled in such a manner to a common bearer that from a position in which they extraneously, in unison, substantially form a casing surface in the shape of a cylinder, are adapted to be pivoted into a position in which, extraneously, they form substantially a surface in the shape of a truncated cone; arrangements have also been provided to enable the jaws to be pivotally hinged from one positon into another.

According to the invention, the holder preferably comprises the cylinder of a hydraulic jack, the piston of which is fitted with obliquely adjusted surfaces, interacting with the free ends of the jaws.

An embodiment of the invention will be described in detail below in conjunction with the attached drawings, where FIGURE 1 constitutes a radial cross section of a device according to the invention; FIGURE 2, a birdseye view along the line II-II in FIGURE 1; FIGURE 3, substantially a cross section corresponding to FIGURE 1, but with the device set in a different operational position, and FIGURE 4, a view in perspective and on a smaller scale of a jar produced by means of the device according to the invention.

In the drawings, the numeral 1 denotes a vertical cylinder, one end of which is closed by means of a head or lid 3, secured in position by the bolts 2, and adapted to be displaced in relation to a stationary piston 4, the shank of which is fixed by the bolts 5 to a horizontal metal plate 6, forming part of a stand not shown. The piston is provided with an axially extending central duct 7, opposite which, in the metal plate 6, has been arranged an aperture 8 for the purpose of enabling the connection of a not shown conduit for application of hydraulic power supplied through the duct 7 to the cylinder chamber 9 at the top of piston 4.

The cylinder 1 is surrounded by a number of jaws 10 having the shape of segments of a cylinder which, by means of hook-shaped end portions 11 at the top end are pivotally attached to a rim 12 which projects upwardly from the cylinder head 3. On the inside at the lower end, the said jaws 10 are provided with rotatably journalled rollers 13, adapted to bear against the skirt 14 of the piston which widens conically in the direction of the cylinder.

In the inoperable condition of the device, i.e. when no hydraulic power is being supplied, the cylinder, in relation to the piston, will occupy the position shown in FIGURE 1, in which the underside of the cylinder head 3 is in direct contact with the top surface of the piston 4. The rollers 13 at the bottom end of the jaws 10 then bear against the tapering piston skirt 14 close to its lower end portion with the lesser diameter, and in such case, the jaws will occupy a position where they extraneously 3,350,914 Patented Nov. 7, 1967 in unison will form substantially a surface in the form of a cylinder casing. Upon hydraulic power being applied to the cylinder chamber 9 at the top of the piston 4 through the duct 7 passing through the said piston, the cylinder 1, and thus also the jaws 10, are forced upwards in relation to the stationary piston. In the course of this movement, the jaws 10, due to the rollers 13 hearing against the upwardly widening piston skirt 14, are made to pivot outwards to the position shown in FIGURE 3, in which position the outwardly turned sides of the jaws, in unison, form a cylinder casing surface substantially into the shape of a truncated cone. Upon release of the pressure in the cylinder chamber 9, the cylinder 1 returns to normal, and the jaws 10, under the influence of gravitation, also return to the original position as shown in FIG- URE 1.

For production of an object shaped as a truncated cone with the aid of the device described above, a job or workpiece designated A, and indicated by dash-dot lines in FIGURE 1, and comprising a sheet metal cylinder with a diameter slightly larger than the diameter of the cylinder formed by the jaws, is set up around the jaws 10 in the position of the device shown in FIGURE 1. Upon application of hydraulic power, the lower ends of the jaws 10 will pivot outwards in the manner described above, and thus cause the sheet metal blank A to be moulded to the corresponding shape. Subsequent to the cylinder 1 and the jaws 10 having been caused to resume the position shown in FIGURE 1, the treated blank can be removed from the device.

The embodiment illustrated in the drawings is also provided with arrangements for making impressions near the small end of the blank in order to facilitate the stacking of a number of such blanks, arranged one inside the other, without the blanks becoming wedged. These arrangements include not only dome-shaped recesses 15 at the outside of some of the jaws close to the top end shown in cross section of the jaw (see FIGURE 2) but also a hydraulic cylinder 16 arranged opposite each one of the said recesses, the piston of which cylinder, at the free end of the shank, carries a dome-shaped head 17 of a form corresponding to that of the said recesses 15. Whilst the blank thus is in the act of being moulded to the shape shown in FIGURE 3, the heads 17 are brought to bear against the blank to produce an impression 18 of the same shape and form as the recesses 15. Only one cylinder 16 with its head 17 has been shown in FIGURE 2, whereas the location of the remaining cylinders has been indicated by the arrows marked by the numeral 19. The location of the impressions 18 in the finished blank is shown in the perspective view of FIGURE 4, where dash-dot lines indicate the location of blanks of the same shape stacked in the blank indicated by continuous lines. As evident from FIGURE 4, the impressions 18 will thus form a support for the bottom edge of the blank immediately above in the stack.

The invention is not confined to the embodiment shown in the drawings and described by way of example in the above. It can be modified in respect of its details without deviating from the basic principle of the invention.

What I claim is:

1. Device for the production from cylindrical blanks of sheet metal objects of a truncated cone configuration comprising a fixed piston having a fluid passageway therein and oblique faces at one end, a cylinder slideably mounted on said piston, a series of jaws each forming a segment of a cylinder, surrounding said cylinder and 3 pivotally connected at one end to said cylinder, said series of jaws having their other ends in slideable contact with said piston oblique faces whereby a cylindrical blank mounted concentric with said jaws will be given a truncated cone configuration upon the introduction of fluid under pressure into said piston passageway.

2. A device as claimed in claim 1 wherein said cylinder has an upstanding rim, said jaws each have a hooked end pivotally mounted on said rim providing the pivotal connection therebetween.

3. A device as claimed in claim 1 wherein each of said jaws other end carries a roller in contact With said cylinder oblique faces.

References Cited UNITED STATES PATENTS 752,153 2/1904 Grotnes 72-393 5 1,419,619 6/1922 Edwards et al. 72-393 1,567,387 12/1925 Rode 72-393 1,908,521 5/1933 Lindgren 72-393 FOREIGN PATENTS 10 446,120 1/1948 Canada.

778,545 7/ 1957 Great Britain.

RICHARD J. HERBST, Primary Examiner. 

1. DEVICE FOR THE PRODUCTION FROM CYLINDRICAL BLANKS OF SHEET METAL OBJECTS OF A TRUNCATED CONE CONFIGURATION COMPRISING A FIXED PISTON HAVING A FLUID PASSAGEWAY THEREIN AND OBLIQUE FACES AT ONE END, A CYLINDER SLIDEABLY MOUNTED ON SAID PISTON, A SERIES OF JAWS EACH FORMING A SEGMENT OF A CYLINDER, SURROUNDING SAID CYLINDER AND PIVOTALLY CONNECTED AT ONE END TO SAID CYLINDER, SAID SERIES OF JAWS HAVING THEIR OTHER ENDS IN SLIDEABLE CONTACT WITH SAID PISTON OBLIQUE FACES WHEREBY A CYLINDRICAL BLANK MOUNTED CONCENTRIC WITH SAID JAWS WILL BE GIVEN A TRUNCATED CONE CONFIGURATION UPON THE INTRODUCTION OF FLUID UNDER PRESSURE INTO SAID PISTON PASSAGEWAY. 